Posts Tagged ‘hardware based virtualization’

Operations running 24×7 are the key objectives of business continuityin any organization. It is a best practice to establish data centers & sites in different geographic regions with replicated applications and data using geographic redundancy.

Implementing geographic redundancy is the main task which can be done in different ways. Deploying multiple sites & using some software to duplicate the data is the significant investment. Now a days IT professionals build redundant sites as a backup and manually manage data replication and failover to the secondary site when needed. By virtualizing data center resources at both sites, you can turn non-performing assets into an ongoing available asset.

A better practice is to virtualize your server and application resources-a much more cost effective and a better overall architecture. Instead of deploying that very expensive mid-range system, virtualize multiple, low-cost, high-performance servers with applications and data, so when one server fails you are not impacted. This gives you the opportunity to achieve high availability and performance without breaking the bank.

A Virtual Private Server or Virtual Dedicated Server (VPS or VDS) is a method of partitioning a physical server into multiple servers such that each VPS has the appearance and capabilities of running on its own dedicated machine. Each virtual server account have its own operating system, can rebooted independently and have root access, users, IP addresses, memory, processes, files, applications, system libraries and configuration files. It fills the gap between shared hosting and dedicated hosting.

There are two kinds of virtualizations: software based and hardware based.In a software based virtualization environment, the virtual machines share the same kernel and actually require the main node’s resources. This kind of virtualization normally has many benefits in a web hosting environment because of quota incrementing and decrementing in real time with no need to restart the node. The main examples are Virtuozzo, HyperVM, OpenVZ and Xen which is the core kernel of both Virtuozzo and HyperVM.

In a hardware based virtualization, the virtualization mechanism partitions the real hardware resources. In typical implementations, no burst or realtime quota modification is possible; the limits are hard and can only be modified by restarting a virtual machine instance. This kind of environment is potentially more secure in the sense that it is less subject to “Quality of Service crosstalk” between VM instances; on the other hand, its security is typically dependent on the correctness of a larger and more complicated Trusted Computing Base. It is more commonly used in big originations or commercial deployments. Examples include VMware ESX Server, Microsoft Virtual Server and Xen.

These types of hosting accounts are usually used as a stepping stone between your basic shared hosting accounts and dedicated hosting accounts. VPS server provides the flexibility of a dedicated server, users shares the system resources, such as the CPU and memory but unlike shared hosting (a virtual host on a shared hardware server) the file system is fully partitioned. Which provides more up-time and more consistenticy, also root access to the server provides the flexibility to add and change modules and to install your own software’s. You get all of the benefits of having your own dedicated machine, but you still have some limitation as to what you can do with it.

VPS is a much needed plan in between your shared and dedicated hosting. It allows you a little more flexibility than a shared hosting account, but limits you more than a dedicated account.